Package edu.princeton.cs.algs4
Class ThreeSum
 Object

 edu.princeton.cs.algs4.ThreeSum

public class ThreeSum extends Object
TheThreeSum
class provides static methods for counting and printing the number of triples in an array of integers that sum to 0 (ignoring integer overflow).This implementation uses a triply nested loop and takes proportional to n^3, where n is the number of integers.
For additional documentation, see Section 1.4 of Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.
 Author:
 Robert Sedgewick, Kevin Wayne


Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static int
count(int[] a)
Returns the number of triples (i, j, k) withi < j < k
such thata[i] + a[j] + a[k] == 0
.static void
main(String[] args)
Reads in a sequence of integers from a file, specified as a commandline argument; counts the number of triples sum to exactly zero; prints out the time to perform the computation.static void
printAll(int[] a)
Prints to standard output the (i, j, k) withi < j < k
such thata[i] + a[j] + a[k] == 0
.



Method Detail

printAll
public static void printAll(int[] a)
Prints to standard output the (i, j, k) withi < j < k
such thata[i] + a[j] + a[k] == 0
. Parameters:
a
 the array of integers

count
public static int count(int[] a)
Returns the number of triples (i, j, k) withi < j < k
such thata[i] + a[j] + a[k] == 0
. Parameters:
a
 the array of integers Returns:
 the number of triples (i, j, k) with
i < j < k
such thata[i] + a[j] + a[k] == 0

main
public static void main(String[] args)
Reads in a sequence of integers from a file, specified as a commandline argument; counts the number of triples sum to exactly zero; prints out the time to perform the computation. Parameters:
args
 the commandline arguments

